.backtotop {
            height: 48px;
            width: 48px;
            text-indent: -9999px;
            background: url(../image/backtotop.png) 0px 0px no-repeat;
            z-index: 500;
            position: fixed;
            bottom: 6px;
            right: 6px;
        }

        .bottom_back_top_top {
            display: none;
            height: 48px;
            width: 48px;
            text-indent: -9999px;
            z-index: 500;
            
            left: 1169px;
            display: block;
            bottom: 20px;
        }

        .backtotop:hover {
            background-position: 0px -48px;
        }